Abstract Objective: To investigate the relation between sleep quality and glycemic control among type 2 diabetic patients. Methods: Across sectional descriptive design was used; the study sample including 125 diabetic patients was recruited at diabetic clinics in Zagazig University hospitals. The interview questionnaire sheet consists of 4 parts: (1) demographic data, (2) medical history, (3) an Arabic version of the Pittsburgh sleep quality index (PSQI), and (4) glycated hemoglobin A1c (HbA1c) analysis test. Results: The mean of sleep duration was the highest score of PSQI components, 96.8% of diabetic patients had poor sleep quality, and 90.4% of diabetic patients had poor glycemic control. A highly statistically significant relationship was found between HbA1c and sleep quality. Moreover, income, duration of disease and smoking were independent positive predictors of HbA1c level, while the female gender was a statistically significant negative predictor. Additionally, female gender and income were statistically significant independent positive predictors of PSQI score. Conclusions: Poor sleep quality and poor glycemic control were very common among type 2 diabetic patients. There was a highly significant relation between sleep quality and glycemic control.